Production of nitropauaffins



y 20, 1952 H. J. PAssINO ETAL 7 7 PRODUCTION OF NITROPARAFFINS Filed March 27,1947

PARAFFIN RECYCLE GASEOUS PRODUCTS FRACTIONATIION PARAFFINY T WER 2| HYDROCARBONS MR l3- x 1 UNREACTED PARAFFINS REACTION CATAL-YST 20 -lo I2 g ,1 l4 l6 mxmc AND REACTION 1 REACTION REACTION k PREHEATING ZONE B ZONE C 20m: D

ZONEA NITRO- PARAFFINS INVENTORS HERBERT J.PASSINO LOUIS 'C. RUBIN B a. M

' ATTOR N EYS Patented May 20, 1952 "UNITED STATES PATENT ()FFICE PRODUCTION OF NITRQBARAFFINS Herbert J. Passino, Englewood, and Louis C. Rubin, West Caldwell, N. J., assignors to'The M. W. Kellogg Company, Jersey corporation of Delaware City, N. J., a

Application March 27, 1947, Serial No. 737,666

8 Claims. 1

vaporization zone has presented important economic obstacles because of severe corrosion problems arising from the reaction of the nitric acid upon costly equipment. In order to overcome the corrosive eifect of the acid, utilization of highly expensive corrosion-resistant material has heretofore been necessary when theaforementioned nitration technique is practiced.

It is therefore an object of the present invention to provide for an improved process for the manufacture of nitrogen derivatives of parafiin hydrocarbons.

A further object of this invention is to provide an improved process for the direct manu facture of nitrogen derivatives of parafiin hydrocarbons, by nitrating these hydrocarbons with the reaction product obtained from the catalytic oxidation of ammonia.

Other objects and advantages inherent 'in the invention will be apparent from the following more detailed disclosure.

In accordance with the process of this invention, these objects are accomplished, in general, by a method of nitration which comprises the steps of charging ammonia and an oxidizing gas into a reaction system over a suitable catalyst under controlled conditions of temperature, pressure, and reaction time to generate nitric acid and/ or some quantities of oxides of nitrogen in the presence of introduced paraffins or paraffin derivatives, immediately reacting these paraffins with the synthesized nitric acid and/or nitrogen oxides at a temperature slightly below the cracking temperature of the paraffins to form corresponding nitroso-paraflins, subjecting these nitroso-paraflins to further oxidation with an oxidizing gas to form the corresponding nitroparafiins, and separating nitro-paraffins thus obtained from resulting gaseous products.

The details, including additional features and advantages of the process of the invention, will 2 be understood by those skilledin the art from the accompanying drawing which illustrates diagrammatically one form 'of the apparatus employed and capable of carrying out one embodimentof the process of our invention. While the invention will bedescribed in detail by reference to one embodiment of the process employing the apparatus illustrated in the drawing, it should be noted that it is not intended that the.

invention be limited to the embodiment as illustrated, but is capable of other embodiments which may extend beyond the scope of the apparatus illustrated in the drawing. Some of the mechanical elements, which form no part of the invention but are necessary to eifect the transfer or liquids and vapors and to maintain the conditions of temperature and pressure necessary to carry out the function of the apparatus, are omitted in order to simplify the description.

It willbe understood, however, that much equip ment of this nature is necessary and will be supplied byfthose skilled in the art.

Referring to the drawing, ammonia and an oxidizing gas, such as air, oxygen, or oxygen-enriched air are introduced, respectively, through valved charging-lines l0 and H .to a reaction system. This reaction system is illustrated diagrammatically in the drawing by reaction tower [2; which comprises a suitable reaction vessel having a mixing and preheating zone and a series of reaction zones, the functions of which will be hereinafter described in accordance with the process of the invention. The ammonia and oxidizing gas, thus introduced into tower l2, are first passed into a mixing and preheating zone A. In zone A the charging stock thus introduced through lines [0 and l l is mixed, and preferably heated rapidly to a temperature sufficiently high to maintain the proper operating conditions of temperature and pressure in reaction zone B as hereinafter described and into which the mixed and preheated charging stock is next transferred. i

The mixed charging stock of ammonia and an oxidizing gas, thus introduced intoreaction zone B, is passed overa suitable catalytic material under conditions of temperature, pressure, and reaction time eifective to convert by oxidation a substantial proportion of the ammonia to nitric acid in the vapor state. We have found that such oxidation is most efficiently carried out by operating reaction zone B at a temperature within approximately the range of 800 C. to 1000 C. and at a super-atmospheric pressure from as indicated above, the charging stock in zone A should preferably be preheated suiiiciently high to maintain the catalyst mass within the aforementioned temperature range, to effect necessary oxidation without the application of external energy.

The catalytic; material employed in the. oxidation reaction in zone B may be a solid material in a fluid-bed or fixed-bed state. While we have found that alloys of platinum may be overall suitable when used as catalysts in the aforementioned oxidation reaction, other catalysts may be efiectively employed; for example, we may use such catalysts as iron, cobalt, nickel or their oxides. It is also possible to use such catalysts as oxides of manganese and magnesium; dioxides of manganese and zirconium; and vanadium pentoxide. used where such catalysts comprise thoria and rare earth oxides; .cobalti'c oxide and either bismuth'trioxide, aluminum oxide or berylliumoxide; ;manganese dioxide and calcium-oxide: and silica gel and chromic oxide.

As. described above, the mixed charging stock ofpreheated ammonia, and oxidizing gas is passed over the catalyst under conditions of temperature. and pressure within the aforementioned ranges, .for a time-sufficient to oxidize substantial proportions of ammonia to nitric acid inthe vapor state. The, product of the reaction thus produced .in zone B and comprising substantial quantities or. nitric acid, and/or some quantities of oxides of nitrogen is passed. to a reaction zone C where it. is immediately contacted with a. preheated gaseous stream of the parafiin hydrocarbon or a mixture of paraffin hydrocarbons to be nitrated. Parafiins which: are thus to be nitrated, are introduced into zone 6' through valved. line I3. These preheated gaseous paraffinsor parafiin mixtures are introduced into zone through line l3; in such proportions" that the temperature in this zone is maintained slightlybelow thecracking temperature of the introduced paraflins The immediate contact of the synthesizednitric. acid; and/or nitrogen oxides obtained; as. the reactionproduct'from zone B in the. nrocessdescribedabove, with h i r e pa laml silhzonefi results in the formation of thecorresponding nitroso-parafilns, in thi 'zone' as a.- gaseous reaction-product. by reason of; the intermediate reaction of nitric. aci a d/ or nitr enoxidesin .thevapor form produced from their reaction with the introduced uaramns. It willt'h noted; that the immediate reaction oi the t i cid with-narafiins in zone Cifollowi g the ab vementioned; acid synthesis; results in the prevention or theioorrosiv e fe t f the cid upon equ ment...

The gaseous reaction. pro uc s. pro uced in zone, .C' and comprising, substantially corresponding nitroso-paraflins of the, introduced paraflins, as described above, are passed to a reaction zone D. The temperature of the products thus introduced' into zone D is; next reduced to a temperature suitable for further oxidation to form corresponding;nitro-parafiins. To effect such reduction 'in temperature, the' products introduced into zone D are first passed through a heat exchange medium, illustrated diagrammatically in the drawing by heat exchanger l4. Nitrosoparafiinspresent inthereaction product thus reduced mtemperature, are next subjected to further oxidationin zone D- by admixture with an oxidizing gas, such as air,-o-xygen, or oxygenenriched-ai r to form a reaction product, com- In addition other catalysts may be.

prisin substantially the corresponding nitroparaffins of the parafl-lns introduced into zone C through line H3. The oxidizing gas thus employed is introduced into zone D through valved line IS. The reaction product thus produced is withdrawn from zone D through valved line l6.

As described above, the reaction product withdrawn from'zone D through line It, comprises substantially nitro-paraflins. In addition there may also be present unreacted parafiins and other gaseous products wherein the latter may comprise one or more unabsorbed gases. For example, where air or oxygen-enriched air is used as the oxidizing gas introduced into the reaction system through line H and/or line [5, in the process described above, unabsorbed gases thus obtained may comprise a mixture consisting largely of nitrogen, carbon dioxide, and other gases normal- 1y present in the air. The reaction product thus withdrawn from zone D is next transferred through line l5 to an intermediate point ina fractionation tower I1. Tower I! is operated underconditions of temperature and pressure ef fective to separate the higher boiling nitro-paraffins from unreacted paraffins and gaseous prodmentioned reaction product obtained from zone D, 'arewithd-rawn from tower I! at an intermediate point through valved line 20 which is at a point above the inlet of line It into the tower. These paraflins' may be next recycled through valved line-2l into line 13-, with which line 2| connects, for further use in tower I-Z- in the process described above.

In certaininstances, depending upon properties of the paraiiins introduced into zone'C- through line [3, oxidation of corresponding n-i-trosoparafiins in zone D may of necessity be conducted at such low temperatures as to prevent direct fractionation of" the nitro-paraflin thus produced. For -example, when the reaction temperatures in zone D are at or near the boiling point of unreacted paraiiins, it will be necessary .toadd additional heat in order to obtain the desired fraction and reflux conditions in tower IT. The necessity for this preheating or reheating is dependent upon the quantities of the parafli-ns fedinto tower l2 through line I3. In'such cases, the temperatureof the reaction product obtained from zone D-maybe raisedsufiicientlyhighto permit subsequent direct fractionationof nitroparafiins from unreacted paraffins and gaseous products in tower H the process described above Conveniently, this may be accomplishedby transferring the aforementioned reaction product withdrawn from zone Dthrough line I6, via valved line 22, through any conventional heating device; illustrated diagrammatically thedrawing by heat exchanger 23. The reaction product thus. heated to a temperature'sufliciently high to permit subsequent fractionation of nitro-paraffins from other component contained therein, is transferred from heat exchanger 23 through line 24 into line. "5, with which line 24' connects, and is subjected to subsequent fractionation in tower I! in the process described above.-

It will be noted that the aforementioned reaction system, illustrated diagrammatically in the drawing by tower l2, comprises a series of mixing, preheating, and reaction zone in a single vessel for carrying out the process of the invention, as described. However, where so desired, it is possible to carry out the process of the invention in a series of suitable vessels, rather than a single vessel, each of such vessels being adapted to maintain the same function as the corresponding mixing, preheating, or reaction zones illustrated in the drawing by the zones in tower 12.

Although our invention has been described with particular reference to a process for the manufacture of nitrogen derivatives of parafiin hydrocarbons, as shown above, it should be noted that it is not restricted to the nitration of openchain parafiins. The process of the invention may be also similarly applied in the manufacture of nitrogen derivatives of cyclo-parafiins to produce corresponding cyclo-nitro-parafiins; similarly nitro-benzenes may be produced from benzene or benzene derivatives; nitro-toluene from toluene or its derivatives; and nitro-cyclopentane and nitro-cyclohexane from cyclopentane and cyclohexane respectively. In each instance the degree of nitration (mono-, di-, or tri-) substition will depend upon the severity of operating conditions. In addition, while we have described a particular embodiment of our invention for purposes of illustration, it should be understood that various modifications and adaptations thereof which will be obvious to one skilled in the art may be made within the spirit of the inven-' tion as set forth in the appended claims.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

1. The process of manufacturing nitrogen derivatives from paraffin hydrocarbons which comprises the steps of passing ammonia and an oxidizing gas through a heating zone at a temperature between about 800 C. and about 1000 C. and at a pressure between about and about atmospheres in the presence of a catalytic material for a reaction time effective to convert a substantial proportion of the ammonia to nitric acid in the vapor state, contacting the vapors thus produced immediately upon formation with at least one gaseous parafiin hydrocarbon at a temperature slightly below the cracking temperature of said paraffin hydrocarbon to form the corresponding nitroso-paraffin and in an amount in excess of that required to efiect substantially complete consumption of nitric acid thus formed, subjecting said nitroso-paramn to further oxidation at a reduced temperature with an additional quantity of said oxidizing gas to form the corresponding nitro-paraflin, and recovering said nitro-paramn.

2. The process of manufacturing nitrogen derivatives from parafiin hydrocarbons which comprises the steps of passing ammonia and an oxidizing gas through a heating zone at a temperature between about 800 C. and about 1000 C. and at a pressure between about 10 and about 15 atmospheres in the presence of a catalytic material for a reaction time effective to convert a substantial proportion of the ammonia to nitrogen oxides in the vapor state, contacting the vapors thus produced immediately upon formation with at least one gaseous paraffin hydrocarbon at a temperature slightly below the cracking temperature of said paraflin hydrocarbon to form the corresponding nitroso-paraffin and in an amount in excess of that required to effect oxides thus formed, subjecting said nitroso parafiin to further oxidation at a reduced temperature with an additional quantity, of said oxidizing gas to form'the correspondingnitroparafiin, and recovering said nitro-parafiin.

3.. The process as defined by claim 2 inwhich said oxidizing gas comprises essentially free oxygen. a a

4. The process as defined by claim 2 in which said oxidizing gas comprises air. p

5. The process as defined by claim,2 in-which said oxidizing gas comprises oxygen-enriched air.

6. The process. of manufacturing nitrogen derivatives from .parafiin hydrocarbons which comprisesthe steps of passing ammonia andan oxidizing gas through a heating zone at a temperature between about 800 C. and about 1000 C. and at a pressure between about 10 and about 15 atmospheres in the presence of a catalytic material for a reaction time efiective to convert a substantial proportion of the ammonia to nitric oxide in the vapor state, and contacting the vapors thus produced immediately upon formation with at least one gaseous paraflin hydrocarbon at a temperature slightly below the cracking temperature of said paraflin hydrocarbon to form the corresponding nitroso-paraifin and in an amount in excess of that required to effect substantially complete consumption of nitric oxide thus formed, subjecting said nitrosoparafiin to further oxidation at a reduced temperature with an additional quantity of said oxidizing gas to form the corresponding nitroparaiiin, and recovering said nitro-paraffin.

7. The process of manufacturing nitrogen derivatives from parafiin hydrocarbons which comprises the steps of preheating a charging stock comprising ammonia and an oxidizing gas to a temperature between about 800 C. and about 1000 C. and at a pressure between about 10 and about 15 atmospheres, passing said preheated charging stock into a first reaction zone in contact with a catalyst comprising platinum for a time effective to convert a substantial proportion of the ammonia to nitric oxide in the vapor state, passing the vapors thus produced into a second reaction zone, contacting said vapors in said second reaction zone with a gaseous parafiin hydrocarbon at a temperature slightly below the cracking temperature of said paraifin hydrocarbon to form the corresponding nitroso-paraffin and in an amount in excess of that required to effect substantially complete consumption of nitric oxide thus formed, passing the nitroso-parafiin thus formed and unreacted parafiin hydrocarbon into a third reaction zone, subjecting said nitroso-paraflin in said third reaction zone to further oxidation at a reduced temperature with an additional quantity of said oxidizing gas to form the corresponding nitroparaflin, and removing said nitro-paraffin from said third reaction zone.

8. The process of manufacturing nitrogen derivatives from paraifin hydrocarbons which comprises the steps of preheating a charging stock comprising ammonia and an oxidizing gas to a temperature between about 800 C. and about 1000 C. and at a pressure between about 10 and about 15 atmospheres, passing said preheated charging stock into a first reaction zone in contact with a catalyst comprising platinum for a time efiective to convert a substantial proportion of the ammonia to nitric oxide in the vapor state, passing the vapors thus produced into a second reaction zone, contacting said vapors in saidSehcl reeifitieifiiohe witli a gaseousparamn hydi c'firbon'at a; temperature slightly belw the cracking temperature ot saidparamn hydrm carbon to form the corresponding: nitrcsm'pab amn anamafi amount in excess of that requird to effect subsfiafitiallycomplete consum tm'n of nitric? oxide thus formed, passing the nitros'oparaflm thus' forme'ct anci' unreactedparafiin hy-'- drocarbon into a third reaction zone, subjecting said nitros'u-paramn in said third reaction zone to further oxidatidn' Eta reduced 'temperature' with an additibnal'quantityof saidoxmiz'ing gas t6 form the 'cdr'ffipondmg "nitro parafiih; sepa= rating said nitro iiaramn from-unreacted paramnhydrcscarbam and returning un'reactedvpar 15 amn-hydrocarbon to 2 said second reacuon: zone;

HERBERT J PASSING. LDUIs c; RUBIN,

REFERENCES CITED The following references are of record in the file (2f this patent:

UNITED STATES PATENTS Number Name Date 1;967,-66'7 Hass et 21,1. a July 24', 1934 2,109,873 Wilhelm Mar. 1', 1938 2,153,065 Martin Apr. 4, 1939 2,161,475 Landon June 6; 1939- 2,288,091 Hbover June 30, 1942 2,291,345 Rideout July 28, 1942 2;4-18-,-241' Stengel et a1 Apr. 1, 1947 2,455,425 Levyet a1. u h-Dec. 7, 1948: 2,465,984 Nygaard et a1. Mar. 29, 1949' OTHER REFERENCES- Taylor, Ind. Eng. Chem, v01. 19, 1250-2 (1927 

1. THE PROCESS OF MANUFACTURING NITROGEN DERIVATIVES FROM PARAFFIN HYDROCARBONS WHICH COMPRISES THE STEPS OF PASSING AMMONIA AND AN OXIDIZING GAS THROUGH A HEATING ZONE AT A TEMPERATURE BETWEEN ABOUT 800* C. AND ABOUT 1000* C. AND AT A PRESSURE BETWEEN ABOUT 10 AND ABOUT 15 ATMOSPHERES IN THE PRESENCE OF A CATALYTIC MATERIAL FOR A REACTION TIME EFFECTIVE TO CONVERT A SUBSTANTIAL PROPORTION OF THE AMMONIA TO NITRIC ACID IN THE VAPOR STATE, CONTACTING THE VAPORS THUS PRODUCED IMMEDIATELY UPON FORMATION WITH AT LEAST ONE GASEOUS PARAFFIN HYDROCARBON AT A TEMPERATURE SLIGHTLY BELOW THE CRACKING TEMPERATURE OF SAID PARAFFIN HYDROCARBON TO FORM THE CORRESPONDING NITROSO-PARAFFIN AND IN AN AMOUNT IN EXCESS OF THAT REQUIRED TO EFFECT SUBSTANTIALLY COMPLETE CONSUMPTION OF NITRO ACID THUS FORMED, SUBJECTING SAID NITROSO-PARAFFIN TO FURTHER OXIDATION AT A REDUCED TEMPERATURE WITH AN ADDITIONAL QUANTITY OF SAID OXIDIZING GAS TO FORM THE CORRESPONDING NITRO-PARAFFIN, AND RECOVERING SAID NITRO-PARAFFIN. 